Reduce Brain Damage During Stroke

(Ivanhoe Newswire) — A new Ohio State study finds that increased oxygen may help stroke victims lessen their brain tissue damage.

Previous studies have concluded that adding oxygen causes more damage to the brain, but these studies did not account for the status of the brain flow during the time the oxygen is added.

Timing plays a crucial role. The use of supplemental oxygen after blood flow is restored in the brain appears to actually cause harm by unleashing free radicals, Savita Khanna, assistant professor of surgery at Ohio State University was quoted as saying. The resulting tissue damage was worse than stroke-affected tissue damage that received no treatment at all. But, adding the oxygen while blood flow is blocked in the brain is a benefit to the patients, reducing the brain damage.

Researchers tested their theory on five groups of lab rats, each induced with an ischemic stoke, meaning the clot is blocking blood flow to the brain. Groups either received normal oxygen or pressured oxygen, before or after blood flow was restored. One control group did not receive added oxygen. Imaging scans two days after the stroke showed significantly less brain damage in patients who received supplemental oxygen treatment while blood flow was blocked.

Strokes are the third leading cause of death in the United States. Currently the clot-busting drug must be administered within the strokes first three hours to treat effectively, although the average time between a patients stroke and their entrance into a hospital is four hours.

Researchers hope that once technology offers a fast, real-time measurement of blood flow, an oxygen treatment can be used to treat and benefit stroke patients. Without the development of a quick blood flow measurement, experts say adding oxygen remains too high a risk. SOURCE: Presented at the Society for Neuroscience meeting in Chicago, October 19, 2009